Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu May 18 2023 17:28:36 ACUS02 KWNS 181728 SWODY2 SPC AC 181726 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1226 PM CDT Thu May 18 2023 Valid 191200Z - 201200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL TEXAS INTO CENTRAL ARKANSAS... ....SUMMARY... Strong/locally severe storms are expected Friday from parts of the southern Plains eastward across Arkansas to parts of the Lower Mississippi Valley vicinity. ....Synopsis... A strong upper trough will move through the Upper Great Lakes on Friday. Attendant to this system, a surface cold front will extend from the Upper Midwest southwestward into the central/southern Plains. While upper-level ridging will be the primary feature across the West, a modest upper-level low will remain across the lower Colorado River Valley/Baja. Some mid-level flow enhancement across the southern High Plains into the Red River region will promote a weak, secondary surface low/dryline from perhaps southwest Oklahoma into parts of central Texas. ....Central Texas into Arkansas... Precipitation is expected to be ongoing during the morning in Oklahoma in association with an MCV from High Plains convection on Thursday. The location of this feature will determine the northward extent of severe potential. Along and south of the outflow/effective warm front, surface heating of low/mid 60s F dewpoints should promote 1000-1500 J/kg MLCAPE. While shear will not be overly strong, flow enhancement from the MCV will allow for modest storm organization. Initial storms would be capable of large hail before storm interactions and upscale growth occur and damaging wind become the primary concern. Along the dryline in Texas, there is less certainty in terms of storm initiation, particularly with southward extent. However, along the outflow/dryline intersection, enough convergence should exist to initiate thunderstorms. Steeper mid-level lapse rates and greater surface heating farther west should promote larger buoyancy (in excess of 2000 J/kg MLCAPE). Shear will be weaker as will anvil-level winds. Even so, initial storm development again will pose a risk of large hail (potentially up to 2 in.). The main uncertainty is where any potential clustering of storms may occur across the broader Slight risk area. Where this occurs, cold pool organization would bring potential for smaller corridors of greater wind damage potential. The spatial extent of the Slight risk intends to capture the envelope of solutions in guidance. ....South Plains into central New Mexico... Storm development is possible along the higher terrain in New Mexico and along the southward sagging cold front into the South Plains. Modest mid-level winds will be orthogonal to the boundary. A few semi-discrete cells are possible. Isolated large hail and damaging winds may occur before storms move north of the boundary and weaken. ....Arizona... Anomalous moisture in the region due to the upper low will promote widely scattered to scattered storms along the Mogollon Rim. Weak mid-level northeasterly flow could help push a cluster off the terrain, but such a scenario is uncertain. Should this occur, strong wind gusts would be possible. Confidence is too low for introducing unconditional severe probabilities. ...Wendt.. 05/18/2023 $$ = = = To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM. --- SBBSecho 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .